1. Field of the Invention
The present invention relates to a terminal holding structure of a connector that holds a terminal by press fitting a straight portion of the terminal into a terminal holding hole formed on a housing.
2. Description of the Related Art
In a connector that is made of resin and is mounted on a circuit board (PCB), which is provided in a variety of electronic devices, for connecting a connector counterpart side such as a connector for connecting flexible integrated wiring, a straight portion of a terminal is press fitted into a terminal holding hole formed on a terminal holding wall of a housing, and the terminals are thereby being held. In this case, to enhance the holding power of the terminals and to keep a good electrical connection condition with the counterpart side terminals, a variety of conventional terminal holding structures have been developed.
For example, in Japanese Patent Application Laid-open No. 2013-062142 and Japanese Patent Application Laid-open No. 2009-043676, the structures of a terminal in which projecting portions that project in a direction orthogonal to the direction of press fitting into the terminal holding hole and are held in the terminal holding hole are formed in a region of a straight portion corresponding to the terminal holding hole have been disclosed. In this case, the with of the straight portion at the portion on which the projecting portions are formed (vicinity of projecting distal ends) has been made wider than that of the terminal holding hole. Thus, when the straight portion of the terminal is press fitted into the terminal holding hole, the projecting portions are in a state of biting into the inner walls of the terminal holding hole and the terminal is being held in the connector.
Consequently, the displacement of the terminals in the longitudinal direction (the press fitting direction and the opposite direction thereof) can be suppressed and, retreating of the terminals in the direction opposite to the press fitting direction can be prevented when fitting in the counterpart side connector and pushed by the counterpart side terminals. Furthermore, the swing of the terminals in the direction orthogonal to the longitudinal direction (for example, the up-down direction and left-right direction) is suppressed, and thus both ends of the terminals (end portions of the counterpart connector side and of the circuit board side) are prevented from being off from the location dimensions (alignment dimensions).
Meanwhile, for example, in the case of forming the projecting portions on a terminal of a flat-plate shape, when the projecting portions are formed by extrusion in a flat-plate shape by pressing corner portions of a prismatic terminal, the projecting portions become thin. When the straight portion of the terminal is press fitted into the terminal holding hole, the projecting portions cleave the inner walls of the terminal holding hole and cause the resin to plastically deform. Then, along the press-fitting path through which the projecting portions passed, grooves (scratches) are formed on the inner walls. Consequently, the terminal holding power in the direction opposite to the press-fitting direction is reduced, and the terminal may retreat along the grooves and slip out from the terminal holding hole. Furthermore, when the resin that has been spread out with the projecting portions is plastically deformed, the pressing force to the projecting portions is weakened and thus the terminal holding power is reduced.